BAsed on the information (via the link ) you provided, abortion has actually been DECREASING by a LARGE margin since the 1980’s in Japan.
I think abortion is less of a factor in the demographic decrease of population compared to everyone marrying later and having less and less chidlren.
In Japan, no matter how small the amount of babies aborted, they they are still missing brothers and sisters which make for a more solid society. Who knows, a couple of those aborted may have been economic genius's who would have been helping them out right now.
Birth dearth is a global problem. Schwinn and Gerber would be much larger companies right now, however millions of little kids have not been using their products for the last nearly 40 years.